Bump futures from 0.3.19 to 0.3.21 (#669)

Bumps [futures](https://github.com/rust-lang/futures-rs) from 0.3.19 to 0.3.21.
- [Release notes](https://github.com/rust-lang/futures-rs/releases)
- [Changelog](https://github.com/rust-lang/futures-rs/blob/master/CHANGELOG.md)
- [Commits](rust-lang/futures-rs@0.3.19...0.3.21)

---
updated-dependencies:
- dependency-name: futures
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.lock

@@ -10,7 +10,7 @@ api_identity = { path = "../api_identity" }
 backoff = { version = "0.3.0", features = [ "tokio" ] }
 chrono = { version = "0.4", features = [ "serde" ] }
 dropshot = {  git = "https://github.com/oxidecomputer/dropshot", branch = "main", features = [ "usdt-probes" ] }
-futures = "0.3.18"
+futures = "0.3.21"
 http = "0.2.5"
 hyper = "0.14"
 ipnetwork = "0.18"

common/Cargo.toml

@@ -16,7 +16,7 @@ cookie = "0.16"
 crucible-agent-client = { git = "https://github.com/oxidecomputer/crucible", rev = "078d364e14d57d5faa3a44001c65709935419779" }
 # Tracking pending 2.0 version.
 diesel = { git = "https://github.com/diesel-rs/diesel", rev = "ce77c382", features = ["postgres", "r2d2", "chrono", "serde_json", "network-address", "uuid"] }
-futures = "0.3.18"
+futures = "0.3.21"
 hex = "0.4.3"
 http = "0.2.5"
 hyper = "0.14"

nexus/Cargo.toml

@@ -7,7 +7,7 @@ license = "MPL-2.0"
 [dependencies]
 chrono = { version = "0.4", features = [ "serde" ] }
 dropshot = { git = "https://github.com/oxidecomputer/dropshot", branch = "main", features = [ "usdt-probes" ] }
-futures = "0.3.18"
+futures = "0.3.21"
 oximeter = { path = "../oximeter" }
 http = { version = "0.2.5", optional = true }
 uuid = { version = "0.8.2", features = [ "v4", "serde" ] }

oximeter/instruments/Cargo.toml

@@ -14,7 +14,7 @@ chrono = { version = "0.4", features = [ "serde" ] }
 # Only used by the simulated sled agent.
 crucible-agent-client = { git = "https://github.com/oxidecomputer/crucible", rev = "078d364e14d57d5faa3a44001c65709935419779" }
 dropshot = { git = "https://github.com/oxidecomputer/dropshot", branch = "main", features = [ "usdt-probes" ] }
-futures = "0.3.18"
+futures = "0.3.21"
 ipnetwork = "0.18"
 nexus-client = { path = "../nexus-client" }
 omicron-common = { path = "../common" }

sled-agent/Cargo.toml

@@ -6,7 +6,7 @@ license = "MPL-2.0"
 
 [dependencies]
 anyhow = "1.0"
-futures = "0.3.18"
+futures = "0.3.21"
 libc = "0.2.116"
 omicron-common = { path = "../common" }
 postgres-protocol = "0.6.3"